1. Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for transmitting a control signal in a wireless communication system for cooperative multiple point transmission and reception (CoMP).
2. Related Art
Recently, wireless mobile communication systems require high-speed data communication such as multimedia services. Further, there is ongoing research for performance improvement of a user equipment located in a cell edge in a communication system having a multi-cell structure. In particular, research on cooperative multiple point transmission and reception (CoMP) for transmitting a signal by mutual cooperation between cells in the communication system having the multi-cell structure is actively carried out. According to the CoMP, a user equipment, especially the user equipment located in the cell edge, can communicate with a plurality of base station and thus can improve not only a transmit power gain but also signal sensitivity.
The CoMP uses a mechanism which defines cells participating in actual cooperative communication among many cells and reports information on the defined cells to a user equipment. In order to define the cells participating in actual cooperative communication and to report a specific time duration in which the cells are effective, a large amount of control information needs to be exchanged between cells. This may result in the increase of a system overhead and may cause deterioration of system efficiency.
Accordingly, there is a need for a method and apparatus capable of determining cells participating in cooperative communication adaptively to a channel condition without having to exchange an excessive amount of control information and capable of delivering a period in which the determined cells are maintained in a wireless communication system performing CoMP.